The present invention relates to a magnetic film, a manufacturing method therefore and a thin film magnetic head using the magnetic film. In particular, the present invention relates to a structure of a magnetic film capable of generating a strong magnetic field and a method of manufacturing the same.
Magnetic disk drives as information storage devices have been required to increase the data transfer rate and the recording density. Magnetic disks having a high coercivity property have been used as recording media, and therefore, it has been desired to make the recording frequency higher for a higher data transfer rate in the thin film magnetic head. To improve the recording magnetic field conversion efficiency of coil current as much as possible for making the recording frequency higher, it has been desired for the magnetic pole piece to use a material having characteristics of low coercivity in the direction of the difficult axis of magnetization (hereinafter referred to as Hc) or low anisotropic magnetic field (hereinafter referred to as Hk) in order to decrease the hysteresis loss. Further, it has been desired to use a material having high specific resistivity (hereinafter referred to as ρ) for the requirement of reducing the eddy current loss.
In addition, the recording characteristics to a high coercivity medium have been improved to attain higher recording density by using a material having a high saturation magnetic flux density (hereinafter referred to as Bs). JP-A No. 2002-217029 discloses a CoFeNi system alloy as a magnetic material capable of increasing the saturation magnetic flux density Bs to 2.0 T or more, and JP-A No. 2002-208514 discloses a NiFi system alloy as a magnetic material capable of increasing the saturation magnetic flux density Bs to 1.9 T or more.